Heat pump system, defrosting method for a heat pump system, and controller

Abstract

A heat pump system, a defrosting method for the heat pump system, and a controller. The heat pump system includes a heat exchanger assembly for exchanging heat with a fluid medium, the heat exchanger assembly comprised a first heat exchanger and a second heat exchanger arranged in parallel, the second heat exchanger being arranged upstream of the first heat exchanger in the flow direction of the fluid medium, and when the heat pump system is operating in a heating mode and the temperature and/or ambient humidity to which the heat exchanger assembly is currently exposed reach a pre-set value, the second heat exchanger and the first heat exchanger function as a condenser and an evaporator, respectively.

The invention claimed is: 
     
       1. A heat pump system, comprising a heat exchanger assembly for exchanging heat with a fluid medium, wherein the heat exchanger assembly comprises a first heat exchanger and a second heat exchanger arranged in parallel, the second heat exchanger being arranged upstream of the first heat exchanger in the flow direction of the fluid medium, and when the heat pump system is operating in a heating mode and a temperature and/or an ambient humidity to which the heat exchanger assembly is currently exposed reach a pre-set value, the second heat exchanger and the first heat exchanger function as a condenser and an evaporator, respectively, wherein the heat pump system comprises:
 a first four-way reversing valve having an interface D, an interface C connected to a first port of the first heat exchanger, an interface S, and an interface E; 
 a second four-way reversing valve having an interface D, an interface C connected to a first port of the second heat exchanger, an interface S, and an interface E; 
 a compressor having a discharge port connected to the interface D of the first four-way reversing valve and the interface D of the second four-way reversing valve, and a suction port connected to the interface S of the first four-way reversing valve and the interface S of the second four-way reversing valve; 
 a cooler having a port connected to the interface E of the first four-way reversing valve and the interface E of the second four-way reversing valve, and another port connected to a second port of the first heat exchanger and a second port of the second heat exchanger; and 
 a check valve disposed between the interface E of the second four-way reversing valve and the cooler, for preventing a heat exchanging medium in the heat pump system from returning to the interface E of the second four-way reversing valve. 
 
     
     
       2. The heat pump system according to  claim 1 , wherein the second heat exchanger and the first heat exchanger both function as condensers when the heat pump system is operating in the heating mode and the temperature and/or ambient humidity reach a set value, the set value of the temperature being less than the pre-set value of an ambient temperature, and the set value of the ambient humidity being greater than the pre-set value of the ambient humidity. 
     
     
       3. The heat pump system according to  claim 1 , wherein the heat exchanger assembly further comprises one or more additional heat exchangers arranged in parallel or in series with the first heat exchanger, and/or in parallel or in series with the second heat exchanger. 
     
     
       4. The heat pump system according to  claim 1 , wherein the second heat exchanger is configured to enable the amount of heat exchange thereof with the fluid medium to be not greater than the amount of heat exchange between the first heat exchanger and the fluid medium. 
     
     
       5. The heat pump system according to  claim 1 , further comprising:
 a first electronic expansion valve disposed between the another port of the cooler and the second port of the first heat exchanger; and/or 
 a second electronic expansion valve disposed between the another port of the cooler and the second port of the second heat exchanger. 
 
     
     
       6. The heat pump system according to  claim 5 , further comprising a bypass disposed between the another port of the cooler and the second port of the second heat exchanger, and provided with a solenoid valve being closed when the heat pump system is operating in a cooling mode and being closed when the heat pump system is operating in the heating mode and the second heat exchanger and the first heat exchanger both function as evaporators, and a check valve for preventing the heat exchanging medium in the heat pump system from returning to the second port of the second heat exchanger. 
     
     
       7. A heat pump system, comprising a heat exchanger assembly for exchanging heat with a fluid medium, wherein the heat exchanger assembly comprises a first heat exchanger and a second heat exchanger arranged in parallel, the second heat exchanger being arranged upstream of the first heat exchanger in the flow direction of the fluid medium, and when the heat pump system is operating in a heating mode and the temperature and/or ambient humidity to which the heat exchanger assembly is currently exposed reach a pre-set value, the second heat exchanger and the first heat exchanger function as a condenser and an evaporator, respectively, wherein the heat pump system comprises:
 a first four-way reversing valve having an interface D, an interface C connected to a first port of the first heat exchanger, an interface S, and an interface E; 
 a second four-way reversing valve having an interface D, an interface C connected to a first port of the second heat exchanger, an interface S, and an interface E; 
 a compressor having a discharge port connected to the interface D of the first four-way reversing valve and the interface D of the second four-way reversing valve, and a suction port connected to the interface S of the first four-way reversing valve and the interface S of the second four-way reversing valve; 
 a cooler having a port connected to the interface E of the first four-way reversing valve, and another port connected to a second port of the first heat exchanger and a second port of the second heat exchanger; and 
 a bypass device disposed between the interface E and the interface S of the second four-way reversing valve. 
 
     
     
       8. The heat pump system according to  claim 7 , wherein the bypass device includes a capillary tube, and a throttle tube. 
     
     
       9. The heat pump system according to  claim 7 , further comprising:
 a first electronic expansion valve disposed between the another port of the cooler and the second port of the first heat exchanger; and/or 
 a second electronic expansion valve disposed between the another port of the cooler and the second port of the second heat exchanger. 
 
     
     
       10. The heat pump system according to  claim 7 , further comprising a bypass disposed between the another port of the cooler and the second port of the second heat exchanger, and provided with a solenoid valve being closed when the heat pump system is operating in a cooling mode and being closed when the heat pump system is operating in the heating mode and the second heat exchanger and the first heat exchanger both function as evaporators, and a check valve for preventing the heat exchanging medium in the heat pump system from returning to the second port of the second heat exchanger. 
     
     
       11. The heat pump system according to  claim 1 , wherein the fluid medium is air. 
     
     
       12. A defrosting method for a heat pump system, comprising the steps of:
 operating the heat pump system according to  claim 1  in a heating mode; 
 obtaining the temperature and/or ambient humidity to which the heat exchanger assembly in the heat pump system is currently exposed; and 
 determining whether the obtained temperature and/or ambient humidity reach a pre-set value, and if yes, enabling the second heat exchanger and the first heat exchanger in the heat exchanger assembly to function as a condenser and an evaporator, respectively. 
 
     
     
       13. The defrosting method for a heat pump system according to  claim 12 , further comprising the steps of:
 in the heating mode, obtaining the temperature and/or ambient humidity to which the heat exchanger assembly is currently exposed; and 
 determining whether the obtained temperature and/or ambient humidity reach a set value, and if yes, enabling the second heat exchanger and the first heat exchanger to both function as condensers, the set value of the temperature being less than the pre-set value of the ambient temperature, and the set value of the ambient humidity being greater than the pre-set value of the ambient humidity. 
 
     
     
       14. A controller, comprising a processor and a storage for storing instructions, wherein the processor, when the instructions are executed, implements the defrosting method for a heat pump system according to  claim 12 . 
     
     
       15. A defrosting method for a heat pump system, comprising the steps of:
 operating the heat pump system according to  claim 7  in a heating mode; 
 obtaining the temperature and/or ambient humidity to which the heat exchanger assembly in the heat pump system is currently exposed; and
 determining whether the obtained temperature and/or ambient humidity reach a pre-set value, and if yes, enabling the second heat exchanger and the first heat exchanger in the heat exchanger assembly to function as a condenser and an evaporator, respectively.